Building blocks of various shapes, sizes and materials have been in common use for thousands of years. Building blocks are traditionally made from rigid materials such as stone, burnt clay, concrete or wood. Although blocks made from these materials are well adapted to use in construction, they have certain disadvantages. First, building blocks made from stone, burnt clay, concrete and similar materials are heavy and difficult to handle and transport to a construction site. Especially in third world countries where transportation is scarce and often unreliable, the transport of building materials can be a major consideration. Second, the assembly of traditional building materials generally requires a certain level of skill. Third, for reasons of economy and/or their inherent properties most building materials are either impractical or impossible to reuse.
Alternate building systems which provide building blocks that may be laid by relatively unskilled labour have been proposed. One notable example of such a system is described in British patent application 2,140,053 which discloses a number of different shapes for interlocking blocks. The blocks described are preferably molded from cementious or burnt clay materials. Although this system appears to eliminate some of the disadvantages of traditional building blocks, it does not address the problem of transporting heavy, and bulky building blocks to construction sites or the problems inherent in handling such materials.
Transportation of building materials can be a major consideration in certain situations, especially when normal transportation routes are disrupted or destroyed by a natural disaster such as an earthquake, typhoon or the like. Such disruptions can affect transportation routes for months or years. A need has therefore been recognized for a lightweight easily transported building block which can be readily assembled into either a temporary or a permanent shelter by relatively unskilled labor with a minimum of instruction.
It is an object of the present invention to provide a lightweight hollow building block which may be stacked, one inside the other, for efficient transportation and storage.
It is a further object of the present invention to provide a building block which is readily adapted to the erection of a building structure by relatively unskilled labour.
It is yet a further object of the present invention to provide a hollow building block which may be used to erect a building structure and repeatedly reused for the same purpose.